Multiroll stands



Aug 11, 1970 LElFELD ET AL 3,523,439

MULTIROLL STANDS Filed March 29, 1967 3 Sheets-Sheet 2 Aug. 1 1, 1970Filed March 29, 1967 MULTIROLL STANDS 3 Sheets-Sheet 5 Fig- 3 UnitedStates Patent C) US. Cl. 72-241 4 Claims ABSTRACT OF THE DISCLOSURE Inmultiroll stands for rolling metal strips comprising a pair of upper andlower working rolls, reversing rolls, and supporting rollers, thesupporting rollers being a plurality of individual rollers of shortaxial length in axially spaced relationship on the two axes andjournalled to supporting bridges. In the past, the supporting rollerswere in direct contact with the backing rolls, and because of theirconstruction the supporting rollers formed circumferential streaks onthe backing rolls which in turn imparted the streaks to the workingrolls which defaced the strip being formed. To overcome this, and makethe rolls more easily serviceable, the instant invention provides a pairof intermediate rolls between the supporting rolls and the backingrolls.

This invention relates to a multiroll stand for the coldrolling orhot-rolling of strips of steel or of nonferrous metals, with twopositively driven backing rolls, and with working rolls driven byperipheral friction. In a known roll stand for the lateral supporting ofthe working rolls, the working rolls are displaced out of the verticalaxis plane of the driven backing rolls, and are supported, in thedirection of the displacement, by intermediate rolls and by supportingrollers journalled on supporting bridges, on their bodies, thesupporting rollers bearing frictionally on the backing rolls.

The geometry of this system of one-sided lateral supporting of theworking rolls restricts the possibilities of adoption of the structure,because, with a diameter of the working rolls proportioned to the forcesoccurring, the minimum diameter of the working rolls can only amount toabout 14 percent of the diameter of the large driven backing rolls. Witheven smaller diameter working rolls, the supporting rollers approach soclose to the upper and lower working rolls in a vertical plane that nosufiicient intermediate space remains for the unhindered passage of thestock that is being rolled or for stock guides.

A further imperfection of the known roll stand may be seen in the factthat since the supporting rollers each consist of a pluarity ofindividual rollers of short axial length, spaced apart, and since theserollers come into direct contact with the backing roll, which comes intodirect contact with the strip that is being rolled, any imperfections inthe surface of these supporting rollers are liable, by a burnishingaction, to produce tracks on the backing rolls, especially if these arenot very hard. Then, when cold rolling stock with a sensitive surface,these tracks may for instance yield streaks of difi'ering lightreflection on the strip that is being rolled. Where this phenomenon isdisadvantageous, the supporting rollers, in order to obviate it, must beracked away from the large backing rolls, though in this case theadvantage of the simple automatic alignment of the supporting rollerswith their axes parallel is lost, and greater constructional expenditurebecomes necessary.

For the hot-rolling of thin strips, the known construction has thedisadvantage that the stock does not admit "ice of being satisfactorilyshielded against undesirable wetting by the cooling water, which isrequired in large quantities for the cooling of the working rolls andthe intermediate rolls. Even if it should be necessary to cool thestock, the quantities of cooling medium for cooling the rolls and forcooling the stock must be capable of being regulated independently ofone another, in order to enable constant roll-gap conditions to bemaintained, so as to obtain stock of a constant form.

The aim of the invention is to provide a roll stand without thedisadvantages set forth, in which, for the cold-rolling of thin hardstrips, very small diameter working rolls can be employed. Economicallyit is further de sired that the working rolls, worn down in the knownroll stand to the minimum diameter there possible, should be capable,after rehardening and regrinding, of being reinserted in the instantroll stand by simple measures for further use.

For hot-rolling it should be ensured that the cooling medium for thesurface cooling of all the rolls is reliably separated from the stock,and is indepedently adjustable, as regards pressure and quantity, of anyrequired cooling of the rolled stock. Moreover a reliable screening ofthe supporting rollers, with their roller bearings, from the radiationof heat from the stock, must be ensured.

According to this invention, all these requirements are fulfilled by thefact that intermediate rolls bearing upon the supporting rollers areheld in frictional driving connection on the one hand with thepositively driven backing rolls, and on the other hand, by way of areversing roll in each case, with the working rolls, whilst the axes ofthe working roll, reversing roll and intermediate roll in each case areheld in a common plane.

The result is thereby obtained that with the same supporting-rollerdiameter, the diameter of the working rolls can be diminished to about10 percent of the backing-roll diameter. In this way the diameter of theworking rolls in the known construction, already ground down to about 14percent of the diameter of the backing rolls, with the backing-rollsystem according to the invention, admit of being brought into useagain, there always being two rolls located between the supporting rollsand the working rolls, which obviates the transferring of streaks fromthe supporting rollers to the surface of the strip.

The supporting rollers are located so far from the rolling plane that itis easy to shield them from the heat radiated by the stock. Theirpackings are withdrawn from the immediate action of the cooling water.

In a further development of the invention, the journals of the upper andlower intermediate rolls on each side are accommodated in a bearing bodywhich is provided, on the side of the working roll, with a cylinder, thepiston of which is connected with a claw, which, jointly with anoppositely located claw, supports the bearing of the working roll, therebeing arranged, between the working rolls and the intermediate-rollbearings, in the bearing body, in the same plane, a longitudinal guide,in which the bearing of the reversing roll, constructed as a slideblock,is displaceably accommodated. In this way the working roll can be veryeasily exchanged. Owing to the movable reversing roll, the grinding downof the roll can of itself be compensated for, within definite limits.

The upper bearing bodies are provided with holding means. This obviatesany sinking of the upper working roll, when the stock has run out, andany sinking of the bearing bodies, with the reversing rolls and theintermediate rolls, when the working rolls are being changed.

According to a further feature of the invention, the spaces bounded bythe backing rolls, the working rolls, the reversing rolls and theintermediate rolls, are provided with admission and discharge ducts forcooling fluid. These are preferably so arranged that the admission iseffected in the middle of the spaces and the exhaust at their ends. Whenthe roll stand is being used for hotrolling, the cooling medium servingfor cooling the surfaces of the rolls flows through these spaces, whichare sealed from the peripheral surfaces of the rolls concerned.

Two embodiments of the invention are illustrated by way of example inthe accompanying drawings, in which:

FIG. 1 shows a vertical section on the line I-I (FIG. 2) through acold-rolling roll stand;

FIG. 2 shows a horizontal section on the line II-II (FIG. 1) at thelevel of the rolled stock; and

FIG. 3 shows diagrammatically the arrangement of the rolls in ahot-rolling roll stand.

The bodies of two working rolls 1 of a multiroll stand are eachvertically supported against a backing roll 2, and are horizontallysupported, through the medium of reversing rolls 3 and throughintermediate rolls 4 bearing on the backing rolls 2, by supportingrollers 5. They are displaced, in the direction of the supportingrollers 5, out of the common axial plane of the backing rolls 2. Thesupporting rollers 5 are journalled in upper and lower supporting-rollercombs 6, which bear, with their rear sides, against supporting bridges 9arranged between the housings 7 and 8. Vertically, the supporting-rollercombs 6 find an abutment on supporting beams 10, which in themselvesextend parallel to the rolls, and are anchored to the chocks 11. Theupper and lower supporting-roller combs 6 are held in contact with thebeam 10 by pressure-fluid cylinders 12 arranged between them.

The bearings of the intermediate rolls 4 are located in bearing bodies13, in longitudinal guides 14 of which the bearings 15, constructed asslide-blocks, of the reversing rolls 3 are also accommodated. In thebearing bodies 13 are also arranged compressed-air cylinders 16, thepistons 17 of which are connected with claws 18, which serve forcentering the working-roll bearings 19 in the common axial plane of theintermediate rolls 4 and the reversing rolls 3. Between the upper andlower bearing bodies 13 are arranged pressure-fluid cylinders 20, whichsupport the upper bearing bodies, and prevent the intermediate rolls 4and reversing rolls 3 sinking when the working roll 1 is beingdismantled.

For securing the bearings 19 of the working rolls, opposite to theintermediate rolls 4, claws 21 are provided, each of which is slidablein a vertical guide 22 of a slide-piece consisting of a head 23 and aguiding member 24. The slide-piece, thus horizontally displaceabletransversely to the rolls, is guided on the chock 11, its guiding member24 being accommodated in a yoke-like guiding body 25 secured to thechock 11. The piston 26 of a cylinder 27 provided in the guiding body 25is directed towards the back of the head 23.

In the piston 26 is provided a cylinder 28, the piston 29 of whichexerts, upon a transmission lever 30 fulcrumed in the head 23, ahorizontal force, which is transmitted to the claw 21 as a verticalforce directed against the backing roll 2, and thus holds the workingroll 1 against the backing roll 2. In the guiding member 24 of theslide-piece is arranged a cylinder 31, the piston rod 32 of which issecured to the chock 11. Upon working fluid being supplied, theslide-piece, with the claw 21, is drawn back, as a result of which thedismantling of the working rolls 1 is rendered possible.

In the roll stand illustrated in FIG. 3, Working rolls 1 andintermediate rolls 4' of larger diameter are inserted, as isadvantageous for hot-rolling. The additional space required for this isobtained by virtue of the fact that the bearing surfaces of thesupporting bridges 9 for the sup- 7 porting-roller combs 6' are set backso far in relation to the neighbourhood of the housing windows that thesupporting-roller combs 6, with the supporting rollers 5', are shiftedfar out of reach of the housing windows, and between the cheeks of thehousing 7 and 8'.

The supporting-roller combs 6' are bolted to supporting beams 10, which,at their ends, are secured laterally to the chocks 11 by wedges 33. Bymeans of spacing plates or shims 34, the most advantageous position ofthe supporting rollers 5', according to the working roll diameter (wear)in each case, can be brought about.

The spaces 35 enclosed by the peripheral surfaces of the backing rolls2', the intermediate rolls 4', the reversing rolls 3 and the workingrolls 1', are provided with inlets and outlets, not shown, for coolingfluid. In this way the surface cooling of the rolls is reliablyseparated from the rolled stock, and can be regulated independently ofthe cooling of the rolled stock.

We claim:

1. A multiroll stand, comprising: two positively driven backing rolls;two working rolls driven by frictional contact with the backing rolls,the axes of the working rolls being displaced out of the planecontaining the axes of the backing rolls; supporting bridges extendingbetween the housings of the roll stands; a plurality of individualsupporting rollers of short axial length, in axially spaced relationshipon each of two axes and journalled in the supporting bridges; twointermediate rolls respectively bearing against each of the supportingrollers and also bearing against each of the backing rolls; tworeversing rolls respectively bearing against each of the working rollsand also against each of the intermediate rolls; means for keeping theintermediate rolls in frictional driving contact with the backing rolls,and also, through the medium of the reversing rolls, with the workingrolls; and means for maintaining the axes of each respective contactingworking roll, reversing roll and intermediate roll in a common plane.

2. A multiroll stand as claimed in claim 1 wherein the maintaining meanscomprises two sets of bearing bodies in which the ends of the upper andlower intermediate roll are respectively journalled; apiston-and-cylinder unit in each bearing body; bearings in which theends of the working rolls are journalled; a claw connected with thepiston of each of the piston-and-cylinder units; further claws eachsupporting the bearings of one of the working rolls; and longitudinalguides provided in the sides of each of the bearing bodies, and bearingsfor the reversing rolls, constructed as slide-blocks, slidable in thelongitudinal guides.

3. A multiroll stand as claimed in claim 2, further comprising holdingmeans for the upper bearing bodies.

4. A multiroll stand as claimed in claim 1, wherein spaces foraccommodating fluid for cooling the rolls are bounded by parts of theperipheries of the backing rolls, the working rolls, the reversing rollsand the intermediate rolls.

References Cited UNITED STATES PATENTS 2,150,340 3/1939 Rohn 72-2422,909,088 10/1959 Volkhausen 72-241 2,927,489 3/1960 Teutsch 72-2433,003,373 10/1961 Volkhausen 72-243 3,049,949 8/ 1962 Volkhausen 72-2433,192,757 7/1965 Diolot 72-241 3,373,590 3/1968 Knappe 72-243 CHARLES W.LANHAM, Primary Examiner B. J. MUSTAIKIS, Assistant Examiner

